This is definitley been the most commonly asked question. With the variable temperatures that we experience in the spring, do not assume that your grasses are dead. Cool-season grasses emerge as soon as the snow melts, but the warm-season grasses do not begin to grown until ground temperatures are warmer going into May. Grasses such as for Dallas Blues, Northwind, Zebra grass, etc. won't begin growing until early summer.
The moral of the story is.... give your grasses some additional time in spring and try not to get discouraged. If you would like more information on cool-season vs. warm season grasses, click here.